Heat- and pressure-resistant bottle with increased oxygen barrier

ABSTRACT

A bottle exhibiting thick walls, constant material thickness, a hemispherical-shaped base-forming portion and a polygonal-shaped flange. The thick walls increase the bottle&#39;s resistance to pressure, oxygen permeation and heat, over that of traditional bottles. The hemispherical-shaped base increases the bottle&#39;s resistance to pressure, over that of traditional bottles. The polygonal-shaped flange enables processing equipment, including bottle fillers and bottle cappers, to handle the bottle.

BACKGROUND OF THE INVENTION

A plastic bottle is typically designed with thin walls to reducematerial cost. The disadvantages associated with a thin-walled plasticbottle are that it has a relatively low tolerance for internal andexternal oxygen permeation, pressure, and heat. The reduced oxygenbarrier limits the shelf life of the product inside the bottle, and thelow tolerance for pressure and heat limits the selection of processingmethods that can be used to fill, cap and otherwise handle the bottle.Conversely, a plastic bottle with a relatively thicker wall provides agreater oxygen barrier and can withstand greater internal and externalpressure, as well as external heat. This allows the bottle to exhibit anincreased shelf life and be used in more processing methods, includinghigh-temperature filling and vacuum filling.

Further, a bottle made of plastic is typically and substantially flat onthe closed body-forming portion surface to allow the bottle to standupright and move conveniently through processing lines. The disadvantagewith a flat-bottom plastic bottle is that for soft drinks and otherpressure applications, the best design for the bottom of a bottle is ahemispherical one.

Those in the industry will recognize that the aforementioneddisadvantage to a typical bottle, namely thin walls and a flat bottom,are not found in a common bottle preform, the predecessor to a bottle.However, a bottle preform is not made for retail use. There are severalfeatures of a bottle perform that make it unsuitable and impractical asa consumer product, such as the downwardly directed axial projection inthe form of an elongated gate at the closed end of many bottle performs,the superfluous material, the challenge with handling the preform duringprocessing due to the hemispherical bottom, and the inconsistent innerdiameter and outer diameter along the body-forming portion.

BRIEF SUMMARY OF THE INVENTION

The purpose of this invention is to provide a bottle that exhibits someof the benefits of a bottle preform without the disadvantages, such thatit can be pragmatically used as a retail consumer bottle. Specifically,the benefits of this resistant bottle are increased tolerance forinternal and external pressure, heat and oxygen permeation, over that oftraditional plastic bottles. The increased tolerance for internal andexternal pressure is a result of the invention's wall thickness andhemispherical-shaped bottom. The increased oxygen barrier and theincreased heat tolerance are a result of the invention's wall thickness.

The benefits of increased resistance to internal and external pressureare that

-   -   (1) the resistant bottle can be used with filling methods        otherwise unsuitable for plastic bottles, such as vacuum        filling;    -   (2) the resistant bottle can be filled at pasteurization        temperatures that exceed maximum temperatures for thin-walled        bottles; and,    -   (3) the resistant bottle is more durable than traditional        plastic bottles.

The benefit of increased oxygen barrier is an increased shelf life forfood-grade and other degradable contents.

The purpose of this invention is to also provide a bottle that can befilled and capped at high speeds. As a circumstance of the hemisphericalbottom, the resistant bottle must sit in a tray during filling, cappingand other processing activities. This could limit processing optionsbecause it is well established in the bottling industry that typicalbottle-filling and bottle-capping machines need to process bottles thatare standing freely upright and stable as they move along a processingline. This permits the machinery to grasp and hold the bottle in placeduring filling and capping. By means of a tray in which the inventionsits, the invention is standing, but it is not freely standing. By meansof a tray, the invention is also stable. To circumvent the need to standfreely, the resistant bottle is processed while in a tray. Apolygonal-shaped stabilizing flange located near the opening of theinvention eliminates the need for the resistant bottle to freely standbecause it permits the resistant bottle to be held in place while seatedin a tray. The flange has an even number of isometric, substantiallystraight outer surfaces; the minimum number of surfaces is six. A simpledevice or ‘jig’ whose perimeter is partially recessed to substantiallymatches more than half of the sides of the polygonal-shaped flange(specifically, one-half the number of surfaces plus one) can be placedagainst the flange of the resistant bottle to hold it in place andprevent rotation. The jig can be fashioned with any number offlange-shaped openings to hold several resistant bottles in a single rowso they may be filled simultaneously using a small, low-cost, multi-headfilling machine. While fixed in the jig, the row of vials may also becapped simultaneously without chance of rotation using a row oflow-cost, pneumatic cappers. The resistant bottles can then be placeddirectly into a shipping carton without ever being removed from thetray. This saves time in the production process by allowing the entirecase of product to be filled into a corrugated container in one step.

The purpose of this invention is to also provide a bottle that allowsfor easy and efficient application of shrink sleeves. The ease ofapplication is partly a result of the invention's wall thickness alongits body-forming portion. It is well known in the bottling industry thata shrink sleeve is typically applied to a bottle after it has beenfilled and cooled when filling said bottle with a high temperatureliquid product (“hot filling”). This is because the thin-walled body ofa typical bottle expands as a result of the hot-filling process; theexpansion will stretch or break the shrink sleeve. In contrast, thebody-forming portion of the invention has thick walls and thus exhibitsnegligible expansion during a hot-filling process. This permits a shrinksleeve to be placed onto the body-forming portion of the resistantbottle prior to filling. If the resistant bottle is hot-filled, thesleeve shrinks as a result of radiant heat emanating outwardly from thehigh temperature product, without the aid of an external heat source,such as a heat tunnel.

The ease of shrink sleeve application is also partly a result of theinvention's constant outer and inner diameters along the resistantbottle's body-forming portion. The shrink sleeve is applied to only thebody-forming portion of the resistant container, which extends from thebottom of the open-ended mouth-forming portion to the top of thehemispherical-shaped base-forming portion. The constant diameter of theresistant bottle allows the shrink sleeve to be sized so that its innerdiameter is only slightly large than the outer diameter of the resistantbottle's body-forming portion. When applied to the resistant bottle, thesleeve requires less heat for shrinkage than what is traditionallyrequired by bottles with inconsistent outer diameters. The constantinner diameter of the invention allows for even heat distribution acrossthe entire surface area of the shrink sleeve. At 170 degrees Fahrenheit,the liquid product induces complete sleeve shrinkage for most bottleplastics. This avoids the need for an additional heat source such as aheat tunnel and saves a step in the overall production process.

This invention is not dependent upon the specific type or design of thebottle finish. Any suitable finish may be used. Further, this inventionis not dependent upon the process by which the resistant bottle is made.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical sectional view of the present inventionparticularly for containing fluids having a thick-walled perimeter and ahemispherical-shaped base-forming portion.

FIG. 2 is a horizontal top view of the present invention.

FIG. 3 is a horizontal sectional view of the present invention takengenerally along the line 3-3 of FIG. 1 and shows the specific crosssection of the body-forming portion.

DETAILED DESCRIPTION OF THE INVENTION

Body-forming portion 1 of the invention as shown in FIG. 1 iscylindrical and hollow with a minimum wall thickness 5 of 1.5 mm and amaximum wall thickness of 4 mm. The base-forming portion 2 is hollow andclosed at the hemispherical end with a minimum wall thickness 5 of 1.5mm and a maximum wall thickness of 4 mm. The mouth-forming portion 3 ishollow and open with a minimum wall thickness 5 of 1.5 mm and a maximumwall thickness of 4 mm.

Extruding from the outer perimeter of the mouth-forming portion 3 andperpendicular to the cylindrical surface area of the body-formingportion is a polygonal-shaped flange 4 as shown in FIG. 1 and FIG. 2exhibiting a minimum of six substantially straight sides. The number ofsides is even. FIG. 2 shows a top view of the mouth-forming portion.

1. A hollow, cylindrical-shaped bottle having an open-endedmouth-forming portion, an intermediate body-forming portion and aclosed, hemispherical-shaped base-forming portion.
 2. A bottle asdefined in claim 1 wherein said body-forming portion has constant outerand constant inner diameters for improved heat distribution duringshrink sleeve application.
 3. A bottle as defined in claim 2 whereinsaid body-forming, base-forming and mouth forming portions have aminimum wall thickness of 1.5 mm and maximum wall thickness of 4 mm forincreased stress resistance, increased heat resistance and increasedoxygen barrier.
 4. A bottle as defined in claim 3 wherein saidmouth-forming portion comprises a polygonal-shaped flange perpendicularto the plane of the body-forming portion and where each isometricoutside surface of the flange is substantially straight and used forholding and stabilizing said bottle during processing.